Device and method for sign illumination

ABSTRACT

A device for illuminating an existing sign ( 100 ) having a specific given pattern on its front side, and a method of manufacturing such a device. A removable laminate ( 102 ) is intended to be applied to the front side of the sign, and comprises a mainly transparent cast compound or matrix ( 200 ) and a number of light emitting diodes ( 104 ) embedded in the matrix together with associated connected diode wires. The light emitting diodes are positioned in a specific pattern adapted to the existing pattern of the sign. Furthermore, a control unit ( 110 ) is configured to provide the light emitting diodes with electric current from a source of power supply ( 112 ) connected to the control unit, and to control the current feeding to the light emitting diodes in accordance with a predetermined scheme.

TECHNICAL FIELD

The present invention relates to a device and method for illumination ofa sign.

BACKGROUND OF THE INVENTION

When displaying information or other things on a sign, some type ofillumination or reflection is typically used in order to increase thevisibility of the sign, particularly when visibility is reduced in theenvironment by darkness, fog or precipitation. One example of this isroad signs having their front side covered with a light reflectingsurface that increases the visibility of the road sign as it isilluminated by, e.g., a headlight. Some associated drawbacks are that aproperly working headlight must be directed towards the sign, and thatall normal existing road signs provide approximately the same degree ofreflection, even though some signs may be more important to observe thanothers.

Signs may further be provided with one or more separate lampsilluminating the front of the sign at an angle from the side withoutobstructing the sign. Signs also exist having installed lampsilluminating the sign from within inside a light admitting shell made ofplastics or glass. Such external or internal separate lamps aretypically fed with electric current from a power supply network, and arerelatively costly to install and maintain. Further, this type of signillumination is fairly vulnerable to external damage.

A great need may exist for increasing the attention to certain signs. Inthe case of road signs, it is unfortunately common that road-users lookat a sign in a routine fashion without observing its significance, whichin the worst case may result in an accident. In particular, in areaswhere a relatively great number of subsequent signs frequently occur,the risk increases for signs more important than others with respect toroad safety being overlooked. Road-users should be able in good time tocatch sight of certain important road signs, e.g. at speed limits,pedestrian crossings, schools and at crossings where drivers must giveway to traffic or must stop.

DE 29701729 U1 discloses a road sign provided with light emitting diodesintegrated in the sign in a fixed pattern which are provided withelectric current from a solar collector. Some drawbacks with thissolution are that the sign must initially be built with the lightemitting diodes installed, and that a relatively significant operationis required to repair or modify the illumination pattern afterwards.

In general, there is a great need for a relatively inexpensive andsturdy solution for providing existing signs with illumination ofoptional strength and pattern in a simple and flexible manner, e.g. inorder to increase the attention therefor.

SUMMARY OF THE INVENTION

It is an object of the present invention to provide a solution to theabove-mentioned problems. This object and others are obtained by adevice for illuminating an existing sign having a specific given patternon its front side, and a method of manufacturing such a device. Aremovable laminate is intended to be applied to the front side of thesign, and comprises a mainly transparent cast compound or matrix and anumber of light emitting diodes embedded in the matrix together withassociated connected diode wires, and positioned in a specific patternadapted to the existing pattern of the sign. Furthermore, a control unitis configured to provide the light emitting diodes with electric currentfrom a source of power supply connected to the control unit, and to turnon and off the light emitting diodes in accordance with a predeterminedscheme.

The invention solves the problem of providing illumination to alreadyexisting signs which can be activated in an optional pattern and ofoptional strength and scheme, e.g. in order to increase the attentiontherefor. This solution does neither significantly affect the existingappearance and any visual effects of the signs, such as reflections.

BRIEF DESCRIPTION OF THE DRAWINGS

The invention is described in more detail by means of preferredexemplary embodiments with reference to the appended drawings:

FIG. 1 is a schematic basic drawing of an illumination arrangement for aroad sign.

FIG. 2 is a detailed sectional view of a removable laminate having lightemitting diodes, according to a preferred embodiment.

FIGS. 3, 4 a and 4 b illustrate schematically a few examples of howlight emitting diodes can be connected to a power source.

DETAILED DESCRIPTION OF EMBODIMENTS

In FIG. 1, a basic drawing is shown of an illumination arrangement for asign 100 configured with a specific given pattern on its front side, inthis case a stop sign. According to the present invention, the frontside of the sign 100 is provided with a removable and basicallytransparent laminate 102 in which a number of light emitting diodes 104are embedded and positioned in a specific pattern which is somehowadapted to the existing pattern and/or exterior outline of the sign. Inthe figure, only a few light emitting diodes are shown, although thenumber and positions of which of course can be selected as entirely freeof choice within the scope of the invention, in order to obtain adesired lightning effect. The laminate 102 may be designed to completelyor partly cover the front side of the sign 100, without obscuring thepattern of the sign, since the laminate is transparent. Thus, when thelight emitting diodes are turned on, the visual appearance of the signpattern can be intensified in order to catch the attention on this sign.

In this example, the light emitting diodes 104 in the laminate arecoupled to a connection contact 106 arranged at an edge side of thelaminate 102. The light emitting diodes 104 are connected to a controlunit 110 by means of the connection contact 106 and a feeding line 108,the control unit 110 being configured to provide electric current to thelight emitting diodes from a source of power supply 112 connected to thecontrol unit. The power source may be, e.g., a battery, or a transformerconnected to a power supply network 114, or an accumulator connected toa solar collector 116. This invention is not limited to any specifictype of power source or power supply. However, in the case of roadsigns, it is advantageous to use a solar collector, since neither wireinstallation to a power supply network nor battery maintenance andreplacements are then required.

In FIG. 2, a section view is shown of a preferred embodiment of alaminate 102 in more detail, which is included in an illumination deviceas described above. The laminate 102 comprises a transparent castcompound or matrix 200 of a suitable material allowing that the lightemitting diodes are embedded therein, e.g. PVC plastics. The rear sideof the laminate to be attached to the front side of the sign, ispreferably provided with a self-adhering adhesive layer 202 for thispurpose. A peelable protective film 204 made of, e.g., a plastic orpaper material, may preferably be applied on the adhesive layer 202 inorder to facilitate handling of the laminate before being attached tothe sign. The laminate may also be attached to the sign in other ways,e.g. by using pins or clamps, or by applying a liquid glue just beforeassembly. In such cases, the adhesive layer 202 and the protective film204 can of course be omitted. However, it is advantageous if theattachment method allows for release of the laminate from the sign, e.g.for replacement, repair or modification.

As mentioned above, the light emitting diodes 104 are in this exampleconnected to the control unit 110 by means of the connection contact106. Thus, a wire 206 runs in the laminate from each light emittingdiode, through which electric current can be fed to the diode. In FIG.2, only one such diode wire 206 is shown for the sake of clarity, inthis case running from a light emitting diode 104 a to the connectioncontact 106. It should be noted that FIG. 1 illustrates the involvedfunctional components only schematically. Within the scope of theinvention, the control unit 110 and possibly also the power source 112may in practice be arranged immediately adjacent to the laminate as arelatively small unit to which the wires 206 may be directly connected,without an intermediate contact 106 and feeding line 108. Alternatively,the control unit 110 and the power source may be mounted on the rearside of the sign, on a post carrying the sign, or at any other optionaland suitable place.

The control unit 110 is configured to turn on and off the light emittingdiodes according to a predetermined scheme. For this purpose, thecontrol unit 110 comprises a processor, not shown, which can beprogrammed to establish connection and disconnection of the linksbetween the diodes 104 and the power source 112, individually or bygroups. It is also possible to configure the control unit such that thecurrent fed to the diodes is varied in order to obtain a variable lightintensity. The control unit 110, the feeding line 108 and the contact106 may be provided with a plurality of current feeding channels toenable differentiated current feeding to the light emitting diodes.

According to different embodiments, the light emitting diodes may beconnected individually and/or by groups to the current feeding channelsin the control unit 110 via the contact 106 and the feeding line 108.FIG. 3 illustrates that four light emitting diodes 104 are individuallyconnected to the control unit 110, thereby enabling that each diode canbe controlled independently of the other diodes by means ofdifferentiated current feeding in the respective line. In FIGS. 4 a and4 b, four diodes 104 are connected as a group to a common currentfeeding channel in the control unit 110, such that the four diodes arecontrolled uniformly. FIG. 4 a shows a parallel connection and FIG. 4 bshows a serial connection.

Within the scope of the invention, the laminate 102 may thus beconfigured with any optional connections of the included light emittingdiodes 104 to current feeding channels, individually and/or in one ormore groups, such that they can be controlled to shine according to apredetermined scheme, by means of suitable programming of the processorin the control unit 110. Selected light emitting diodes may in this waybe turned on and off at certain points in time or at certain intervals.A simple example of such a scheme is that all diodes are turned onduring the dark period of the day/night, or that the sign flashes orpulsates during rush hour, etc, which to some extent will provide energysavings. A “flowing” light can also be produced by means of suitablecontrolling of the light emitting diodes. Further, it is possible tocreate various decorative effects for other applications, such asadvertising displays.

The present invention embraces also a method of manufacturing a devicefor illuminating an existing sign provided with a specific pattern. Themanufacturing method includes casting a laminate 200, such that aplurality of light emitting diodes 104 together with associatedconnected wires 206 are embedded in a cast compound or matrix 200.During casting, the light emitting diodes 104 are positioned in apattern that corresponds to the existing pattern of the sign. Aself-adhering adhesive layer 202 may also be applied to the rear side ofthe laminate. However, this step may be omitted if another attachmentmethod is selected.

The diode wires 206 are further connected to a control unit 110 and asource of power supply 112, as described above. The diode wires 206 areconnected either directly to the control unit 110 or by means of acontact 106 on the laminate and a feeding line 108 if the control unit110 is placed at a distance from the laminate. The laminate can then beattached to the existing sign in a position such that the diode patternmatches the existing pattern of the sign, and the control unit 110 canbe activated to make the light emitting diodes shine according to apredetermined scheme which is programmed in the control unit. The stepsof connecting the light emitting diodes to the control unit and ofapplying the laminate to the sign may of course be executed in anysuitable sequence order.

The described embodiments do not limit the invention, which is generallydefined by the following claims.

1. A device for illuminating an existing sign having a specific givenpattern on its front side, comprising: a removable laminate intended tobe applied to the front side of the sign, and comprising a mainlytransparent cast compound or matrix and a number of light emittingdiodes which are embedded in the matrix together with associatedconnected diode wires and positioned in a specific pattern adapted tothe existing pattern of the sign, and a control unit configured toprovide the light emitting diodes with electric current from a source ofpower supply connected to the control unit, and to control the currentfeeding to the light emitting diodes in accordance with a predeterminedscheme.
 2. A device according to claim 1, wherein the control unitcomprises a processor which is programmable to execute saidpredetermined scheme.
 3. A device according to claim 1 wherein the rearside of the laminate is provided with a self-adhering adhesive layer forattaching the laminate to the sign.
 4. A device according to claim 1,wherein the diode wires can be directly connected to the control unit.5. A device according to claim 1, wherein a connection contact isarranged at an edge side of the laminate, wherein the diode wires can beconnected to the control unit by means of the connection contact and afeeding line.
 6. A device according to claim 1, wherein the control unitcomprises a plurality of current feeding channels, wherein the lightemitting diodes can be connected individually and/or by groups to thecurrent feeding channels in the control unit, such that selected lightemitting diodes can be turned on and off at certain points in time or atcertain intervals.
 7. A method of manufacturing the device of claim 1,comprising the following steps; casting a laminate comprising a castcompound or matrix and a plurality of light emitting diodes embedded inthe matrix together with associated wires, such that the light emittingdiodes are positioned in a specific pattern adapted to the existingpattern of the sign, connecting the diode wires to a control unit and asource of power supply, wherein the control unit is configured tocontrol the current feeding to the light emitting diodes in accordancewith a predetermined scheme, and applying the laminate to front side ofthe existing sign in a position such that the diode pattern matches theexisting pattern of the sign.
 8. A method according to claim 7, whereinthe diode wires are directly connected to the control unit.
 9. A methodaccording to claim 7, further comprising the step of connecting thediode wires to the control unit by means of a contact on the laminateand a feeding line.
 10. A method according to claim 7, furthercomprising the step of connecting the light emitting diodes individuallyand/or by groups to a plurality of current feeding channels in thecontrol unit, such that selected light emitting diodes can be turned onand off at certain points in time or at certain intervals.
 11. A methodaccording to claim 7, further comprising the step of providing the rearside of the laminate with a self-adhering adhesive layer for attachingthe laminate to the sign.
 12. A device for illuminating a sign having apattern of indicia on its front side, comprising: a removable laminateadapted to be applied to the front side of the sign, said removablelaminate comprising a substantially transparent material and a number oflight emitting diodes which are embedded in the substantiallytransparent material together with associated, connected diode wires,and a control unit configured to provide the light emitting diodes withelectric current from a power supply, and to control the currentsupplied to the light emitting diodes, wherein said removable laminatecan be readily removed from said front of said sign and further whereinsaid control unit can selectively turn individual light emitting diodesoff while other light emitting diodes remain turned on.